Cuban president Raul Castro backs greater gay rights and ending discrimination against homosexuals, his daughter Mariela, a famed sexologist, said during a colourful gay rights march in Havana.

Traditionally stigmatised in Cuba, homosexuality was fiercely repressed for many years by the regime, which interned homosexuals in work camps in the 1960s and ostracized them in the 1970s under the rule of Fidel Castro.

Raul Castro succeeded his brother Fidel as president in 2006.

Mariela Castro runs Cuba's National Centre for Sex Education (CENESEX) and is an outspoken advocate for the rights of homosexuals and transsexuals in Communist-ruled Cuba.

"He has done some advocacy work, speaking of the need to make progress in terms of rights based on sexual orientation and gender identity," Ms Castro told reporters.

"The Cuban president ... has been talking about this issue, but he has not made it public. It is surely part of his strategy," she added, when asked if her father backed her campaign to legalize civil unions for gays and lesbians.

[Raul Castro] has said that ... we cannot make progress if we continue to live with these prejudices.

Mariela Castro

"He himself has said that ... we cannot make progress if we continue to live with these prejudices."

Ms Castro is pushing for passage of legislation that would legalize same-sex unions, but stops short of endorsing gay marriage.

She is hopeful that politicians will take up the bill sometime this year.

The president's daughter led a colourful conga line that was part of a march through the streets of Havana attended by about 400 transvestites as part of festivities marking the Fifth Cuban Day Against Homophobia.

In January, Cuba's Communist Party Congress resolved "to fight against all forms of discrimination, including against sexual discrimination, and discrimination on the basis of sexual orientation and sexual identity."

"It's a hugely important first step," Ms Castro said earlier this week.